Systems and methods for running tubulars into subterranean wellbores

ABSTRACT

A guide assembly for running a liner through a borehole extending through a subterranean formation, the guide assembly having a central axis, a first end configured to be coupled to the liner, and a second end opposite the first end. The guide assembly includes a guide shoe disposed at the second end, a drive assembly including a radially outer housing, and a rotor concentrically disposed in the housing. The rotor has a first end distal the guide shoe and a second end fixably coupled to the guide shoe, and is configured to rotate about the central axis relative to the housing about the central axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent applicationSer. No. 61/971,400 filed Mar. 27, 2014, and entitled “Systems andMethods for Running Tubulars into Subterranean Wellbores,” which ishereby incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND

Embodiments described herein relate generally to systems and methods foraccessing and producing hydrocarbons from a subterranean formation. Moreparticularly, the invention relates to systems and methods for liningsubterranean boreholes.

In drilling operations, a large diameter hole is drilled from thesurface to a selected depth. Then, a primary conductor secured to thelower end of an outer wellhead housing disposed at the surface, alsoreferred to as a low pressure housing, is run into the borehole. Cementis pumped down the primary conductor and allowed to flow back up theannulus between the primary conductor and the borehole sidewall.

With the primary conductor secured in place, a drill bit is loweredthrough the primary conductor to drill the borehole to a second depth.Next, an inner wellhead housing, also referred to as a high pressurehousing, is seated in the upper end of the outer wellhead housing. Astring of casing secured to the lower end of the inner wellhead housingor seated in the inner wellhead housing extends downward through theprimary conductor. Cement is pumped down the casing string, and allowedto flow back up the annulus between the casing string and the primaryconductor and out cement ports extending radially through the outerwellhead housing. The drill bit is lowered through the primary conductorand the casing string and drilling continues.

To ensure well integrity, the open borehole extending from the primaryconductor and casing string is lined with a tubular liner, which can bein the form of successive casing strings, coiled tubing, or the like.Following drilling, the liner is typically run from the surface throughthe primary conductor, any previously installed casing, and the openborehole to the desired depth, and then cemented in place. While runningthe liner through the open borehole, the liner may get hung up or stuckon cutting debris, a ledge, or other obstruction that interferes withthe advancement of the liner. A stuck liner may require remedialactions, result in delays, and added costs. A guide shoe may be providedat the lower end of the liner to facilitate its advancement through theopen borehole and around obstructions. However, conventional guide shoesexhibit varying degrees of success, and further, some conventional guideshoes do not allow for cementing without an additional trippingoperation.

BRIEF SUMMARY OF THE DISCLOSURE

These and other needs in the art are addressed in one embodiment by aguide assembly for running a liner through a borehole extending througha subterranean formation. The guide assembly has a central axis, a firstend configured to be coupled to the liner, and a second end opposite thefirst end. In an embodiment, the guide assembly includes a guide shoedisposed at the second end, a drive assembly including a radially outerhousing, and a rotor concentrically disposed in the housing. Inaddition, the rotor is configured to rotate about the central axisrelative to the housing about the central axis. Further, the rotor has afirst end distal the guide shoe and a second end fixably coupled to theguide shoe.

These and other needs in the art are addressed in one embodiment by aguide assembly for running a liner through a borehole extending througha subterranean formation. The guide assembly has a central axis, a firstend configured to be coupled to the tubular, and a second end oppositethe first end. In an embodiment, the guide assembly includes a guideshoe disposed at the second end and a drive assembly including aradially outer housing and a rotor rotatably disposed in the housing. Inaddition, the rotor has a first end distal the guide shoe, a second endfixably coupled to the guide shoe, and an outer surface extending fromthe first end of the rotor to the second end of the rotor, wherein theouter surface of the rotor includes a plurality ofcircumferentially-spaced parallel helical flights. Further, the assemblyincludes an inlet guide disposed about the rotor and axially positionedbetween the first end of the rotor and the plurality of helical flightsof the rotor, wherein the inlet guide has an outer surface including aplurality of circumferentially-spaced parallel helical flights.Moreover, each of the helical flights of the rotor spiral about thecentral axis in a first direction and the plurality of helical flightsof the inlet guide spiral about the central axis in a second directionthat is opposite the first direction.

These and other needs in the art are addressed in one embodiment by aguide assembly for running a tubular through a borehole extendingthrough a formation. The guide assembly having a central axis, a firstend configured to be coupled to the tubular, and a second end oppositethe first end. In an embodiment, the guide assembly includes a guideshoe disposed at the second end and a drive assembly configured to drivethe rotation of the guide shoe about the central axis. In addition, thedrive assembly includes a radially outer tubular housing and a rotorrotatably disposed within the housing. Further, the rotor has a firstend distal the guide shoe and a second end fixably coupled to the guideshoe, and includes a bore extending axially from the second end of therotor and a port extending radially from an outer surface of the rotorto the bore. Moreover, the guide shoe includes an inner fluid cavity influid communication with the bore of the rotor and a port extending fromthe inner fluid cavity to an outer surface of the guide shoe.

Embodiments described herein comprise a combination of features andadvantages intended to address various shortcomings associated withcertain prior devices, systems, and methods. The foregoing has outlinedrather broadly the features and technical advantages of the invention inorder that the detailed description of the invention that follows may bebetter understood. The various characteristics described above, as wellas other features, will be readily apparent to those skilled in the artupon reading the following detailed description, and by referring to theaccompanying drawings. It should be appreciated by those skilled in theart that the conception and the specific embodiments disclosed may bereadily utilized as a basis for modifying or designing other structuresfor carrying out the same purposes of the invention. It should also berealized by those skilled in the art that such equivalent constructionsdo not depart from the spirit and scope of the invention as set forth inthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the disclosure, reference will now be madeto the accompanying drawings in which:

FIG. 1 is a schematic view of a wellbore and an embodiment of a systemin accordance with the principles described herein for running a linerin the wellbore;

FIG. 2 is a perspective view of the guide assembly of FIG. 1;

FIG. 3 is a perspective cross sectional view of the guide assembly ofFIG. 2;

FIG. 4 is a cross sectional side view of the connection sub of FIG. 2;

FIG. 5 is a partial cut away side view of the drive assembly of FIG. 2;

FIG. 6 is a partial cut away perspective view of the outer housing ofFIG. 2;

FIG. 7 is a cross sectional side view of the outer housing of FIG. 2;

FIG. 8 is side view of a rotor of the drive assembly of FIG. 5;

FIG. 9 is a cross sectional side view of the rotor of FIG. 8;

FIG. 10 is a cross sectional end view of the rotor of FIG. 8;

FIG. 11 is a side view of the inlet guide of the drive assembly of FIG.5;

FIG. 12 is a cross-sectional side view of the inlet guide of FIG. 11;

FIG. 13 is a partial cut away perspective view of the inlet guide ofFIG. 11;

FIG. 14 is a partial cut away end view of the inlet guide of FIG. 11;

FIG. 15 is an enlarged partial cut away side view of the upper end ofthe guide assembly of FIG. 2;

FIG. 16 is an enlarged partial cut away side view of the lower end ofthe guide assembly of FIG. 2;

FIG. 17 is a side view of the guide shoe of FIG. 2;

FIG. 18 is a cross-sectional side view of the guide shoe of FIG. 17; and

FIGS. 19A-19D illustrate schematic side views of alternative embodimentsof guide shoes for use with the guide assembly of FIG. 2.

DETAILED DESCRIPTION

The following discussion is directed to various exemplary embodiments.However, one skilled in the art will understand that the examplesdisclosed herein have broad application, and that the discussion of anyembodiment is meant only to be exemplary of that embodiment, and notintended to suggest that the scope of the disclosures, including theclaims, is limited to that embodiment.

Certain terms are used throughout the following description and claimsto refer to particular system components. This document does not intendto distinguish between components that differ in name but not function.Moreover, the drawing figures are not necessarily to scale. Certainfeatures of the disclosure may be shown exaggerated in scale or insomewhat schematic form, and some details of conventional elements maynot be shown in the interest of clarity and conciseness. Further, somedrawing figures may depict vessels in either a horizontal or verticalorientation; unless otherwise noted, such orientations are forillustrative purposes only and is not a required aspect of thisdisclosure.

In the following discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to . . . .” Also, theterms “couple,” “attach,” “connect” or the like are intended to meaneither an indirect or direct mechanical or fluid connection, or anindirect, direct, optical or wireless electrical connection. Thus, if afirst device couples to a second device, that connection may be througha direct mechanical or electrical connection, through an indirectmechanical or electrical connection via other devices and connections,through an optical electrical connection, or through a wirelesselectrical connection. In addition, as used herein, the terms “axial”and “axially” generally mean along or parallel to a given axis (e.g.,central axis of a body or a port), while the terms “radial” and“radially” generally mean perpendicular to the axis. For instance, anaxial distance refers to a distance measured along or parallel to theaxis, and a radial distance means a distance measured perpendicular tothe axis. Any reference to up or down in the description and the claimswill be made for purpose of clarification, with “up,” “upper,”“upwardly,” or “upstream” meaning toward the surface of the well andwith “down,” “lower,” “downwardly,” or “downstream” meaning toward theterminal end of the well, regardless of the well bore orientation. Insome applications of the technology, the orientations of the componentswith respect to the surroundings may be different. For example,components described as facing “up,” in another application, may face tothe left, may face down, or may face in another direction.

Referring now to FIG. 1, an embodiment of a system 10 for running andadvancing a liner 50 through a borehole 20 is shown. Borehole 20 extendsfrom the surface 30 through a subterranean formation 31. The upperportion of borehole 20 is lined with a primary conductor 21 extendingdownward from a wellhead 22 at the surface 30 and a casing string 23extending from wellhead 22 through primary conductor 21. Casing 23 andconductor 21 are cemented in place. However, the portion of boreholedownhole of casing 23 is open (i.e., it is not cased or lined).Accordingly, system 10 runs liner 50 from the surface through conductor21, casing 23, and borehole 20 to line the open portion of borehole 20disposed downhole of casing 23. In general, liner 50 can be any tubularknown in the art including, without limitation, coiled tubing, casing orcasing string, drill pipe, or the like. Thus, as used herein, the term“liner” is used to refer to any elongate tubular including, withoutlimitation, coiled tubing, casing, drill pipe, pipe string, casingstring, production tubing, or the like.

In this embodiment, system 10 includes a power source 11, a surfaceprocessor 12, a liner reel or spool 13, an injector head unit 14, liner50, and a shoe or guide assembly 100. Power source 11, processor 12,spool 13, and injector head unit 14 are disposed at the surface 30.Power source 11 provides electrical power to system 10 and processor 12controls the operation of system 10. Spool 13 stores liner 50 and paysout liner 50 as it is fed by injector head unit 14 through wellhead 20,conductor 21, and casing 23 into the open portion of borehole 20. Guideassembly 100 is mounted to the lower end of liner 50 and facilitates theadvancement of liner 50 through conductor 21, and casing 23, and theopen portion of borehole 20. An annulus 24 is formed between liner 50and the open portion of borehole 20. Annulus 24 extends to the surface30 and is at least partially filled with cement to secure liner 50 inplace once it is disposed at the desired depth in borehole 20. As willbe described in more detail below, guide assembly 100 allows thecementing of liner 50 without having to trip liner 50 or guide assembly100.

As shown in FIG. 1, liner 50 is jointed pipe that is then deployed bycoiled tubing paid out from coiled tubing reel 13. Further, althoughguide assembly 100 is shown and described as running liner 50 throughthe open portion of borehole 20, in general, guide assembly 100 can beemployed to facilitate the run in of any downhole device or tubularthrough an open portion of a borehole, a cased wellbore, anothertubular, or combinations thereof.

Referring now to FIGS. 2 and 3, guide assembly 100 has a central orlongitudinal axis 105, a first or upper end 100 a coupled to the lowerend of liner 50, and a second or lower end 100 b distal liner 50. Thus,as liner 50 and guide assembly 100 advance through wellbore 20, end 100b leads. In this embodiment, guide assembly 100 includes a connectionsub 110 at upper end 100 a, a guide shoe 180 at lower end 100 b, and adrive assembly 120 axially positioned between sub 110 and guide shoe180. As will be described in more detail below, connection sub 110connects guide assembly 100 to liner 50 and drive assembly 120 powersthe rotation of guide shoe 180.

Referring now to FIGS. 2-4, connection sub 110 is a tubular sub thatconnects drive assembly 120 to lower end of liner 50. Sub 110 has acentral axis coaxially aligned with axis 105, a first or upper end 110 acoincident with end 100 a, a second or lower end 110 b coupled to driveassembly 120, a radially outer cylindrical surface 111 extending axiallybetween ends 110 a, 110 b, and a radially inner surface 112 extendingaxially between ends 110 a, 110 b. In this embodiment, upper end 110 acomprises an internally threaded box end (internal threads not shown)that threadably connects sub 110 to a mating pin end at the lower end ofliner 50.

Inner surface 112 of connection sub 110 includes a first cylindricalsection 112 a extending axially from end 110 a to a downward-facingannular planar shoulder 113 a, a second cylindrical section 112 bextending axially from shoulder 113 a to a frustoconical annularshoulder 113 b, and an internal threaded section 112 c extending axiallyfrom shoulder 113 b to end 110 b. First cylindrical section 112 a isdisposed at a diameter that is less than the diameter of secondcylindrical section 112 b. As will be described in more detail below,internally threaded section 112 c defines a box end that threadablyconnects connection sub 110 to a mating pin end of drive assembly 120.

Referring now to FIGS. 3 and 5, drive assembly 120 has a first or upperend 120 a coupled to connection sub 110 and a second or lower end 120 bcoupled to guide shoe 180. In this embodiment, drive assembly 120includes a radially outer housing 121, a rotor 130 rotatably disposedwithin housing 121, an inlet guide 140 disposed about rotor 130 withinhousing 121, and a retention cap 175. Housing 121, rotor 130, and inletguide 140 each has a central axis coaxially aligned with axis 105. Anannular washer or spacer 170 is disposed about rotor 130 and axiallycompressed between retainer cap 175 and first bearing assembly 150.

Referring now to FIGS. 5-7, outer housing 121 is a tubular having afirst or upper end 121 a threadably attached to lower end 110 b ofconnection sub 110, a second or lower end 121 b axially adjacent guideshoe 180, a radially outer surface 122 extending axially between ends121 a, 121 b, and a radially inner surface 125 extending axially betweenends 121 a, 121 b. Outer surface 122 includes an externally threadedsection 123 a at upper end 121 a, an upward-facing planar annularshoulder 123 b axially adjacent section 121 a, a downward-facing planarannular shoulder 123 c at lower end 121 b, and a cylindrical section 123d extending axially between shoulders 123 b, 123 c. Externally threadedsection 123 a defines a pin end that threadably engages matinginternally threaded section 112 c of connection sub 110, therebyconnecting housing 121 to sub 110.

As best shown in FIGS. 6 and 7, inner surface 125 includes a firstcylindrical section 126 a extending axially from end 121 a to anupward-facing annular frustoconical shoulder 126 b, a second cylindricalsection 126 c extending axially from shoulder 126 b to a downward-facingplanar annular shoulder 126 d, and a third cylindrical section 126 eextending axially from shoulder 126 d to end 121 b. Second cylindricalsection 126 c is disposed at a diameter that is less than the diameterof first cylindrical section 126 a and third cylindrical section 126 e.Thus, shoulders 126 b, 126 d extend radially inward from sections 126 a,126 e, respectively, to section 126 c.

In this embodiment, outer housing 121 is formed by multiple tubularmembers coupled together end-to-end. However, in general, the outerhousing (e.g., outer housing 121) can be formed as a monolithic tubularor by coupling any number of tubular members together.

Referring now to FIGS. 3, 8, and 9, rotor 130 is an elongate memberhaving a first or upper end 130 a, a second or lower end 130 b, and aradially outer surface 131 extending axially between ends 130 a, 130 b.As best shown in FIGS. 8 and 9, and moving axially from end 130 a to end130 b, outer surface 131 includes an externally threaded section 131 aat end 130 a, an annular recess 131 b axially adjacent threaded section131 a, a first cylindrical section 131 c, an upward-facing annularplanar shoulder 132 a, a flighted section 135, a second cylindricalsection 131 d, an upward-facing annular frustoconical shoulder 132 b, athird cylindrical section 131 e, an annular recess 131 f, and anexternally threaded section 131 g at end 130 b. Threaded section 131 ais threadably attached to retention cap 175, first cylindrical section131 c extends axially from annular recess 131 b to shoulder 132 a,flighted section 135 extends axially between shoulder 132 a and secondcylindrical section 131 d, shoulder 132 b is axially positioned betweencylindrical sections 131 d, 131 e, third cylindrical section 131 eextends axially from shoulder 132 b to annular recess 131 f, andexternally threaded section 131 g is threadably attached to guide shoe180.

Referring now to FIGS. 8-10, flighted section 135 of outer surface 131includes a plurality of circumferentially-spaced parallel flights 136that extend helically about axis 105 and axially between shoulder 132 aand section 131 d. In this embodiment, rotor 130 includes threeuniformly circumferentially-spaced flights 136. Thus, flights 136 areuniformly angularly spaced 120° apart about axis 105. However, ingeneral, the rotor (e.g., rotor 130) can include any suitable number offlights (e.g., two, three, four, or more flights 136), and further, thecircumferential spacing of the flights can be uniform or non-uniform.

Each flight 136 has a first or upper end 136 a, a second or lower end136 b, lateral sides 137 a, 137 b extending between ends 136 a, 136 b, aradially inner base 138 a integral with the remainder of rotor 130 andextending between ends 136 a, 136 b, and a radially outer generallycylindrical surface 138 b distal the remainder of rotor 130 andextending between ends 136 a, 136 b. In this embodiment, each flight 136has the same length measured between ends 136 a, 136 b. Radially outersurface 138 b of each flight 136 is disposed at a uniform radiusR_(138b), and each flight 136 has a height H₁₃₆ measured radially fromits base 138 a to its outer surface 138 b. In this embodiment, outersurfaces 138 b of flights 136 do not engage housing 121, and thus,radius R_(138b) is less than the inner radius of housing 121 alongcylindrical section 126 a. In general, the radius R_(138b) of each outersurface 138 b is preferably between 1/16 and 2.0 in., and each heightH₁₃₆ is preferably between 1/16 and 2.0 in. In this embodiment, radiusR_(138b) of each outer surface 138 b is the same, and in particular, is¼ in.; and each height H₁₃₆ of each flight 136 is the same, and inparticular, is ⅜ in. In addition, each flight 136 is oriented at anacute flight angle θ₁₃₆ relative to a reference plane A perpendicular toaxis 105 in side view, and has a pitch P₁₃₆ equal to the axial length(center-to-center) of one complete turn of flight 136. Flight angle θ₁₃₆of each flight 136 is preferably between 0° and 90°, and more preferablybetween 30° and 60°. Pitch P₁₃₆ of each flight 136 is preferably between½ and 5 revolutions over 12.0 in., and more preferably between 1 and 2revolutions over 12.0 in. In this embodiment, flights 136 are identicaland parallel, and thus, radius R_(138b) of each outer surface 138 b isthe same, flight angle θ₁₃₆ of each flight 136 is the same and pitchP₁₃₆ of each flight 136 is the same. In particular, in this embodiment,flight angle θ₁₃₆ of each flight 136 is 45° and pitch P₁₃₆ of eachflight 136 is 1¼ revolutions over 12.0 in. As best shown in FIG. 10,when the rotor 130 is viewed from above along axis 105, flights 136spiral in a counterclockwise direction.

In this embodiment, flighted section 135 of outer surface 131 alsoincludes a plurality of circumferentially adjacent parallel grooves 139disposed between each pair of circumferentially adjacent flights 136.Grooves 139 offer the potential to facilitate and assist fluid flowthrough drive assembly 120.

As best shown in FIGS. 8 and 9, rotor 130 includes a bore 133 extendingaxially from lower end 130 b and a plurality of uniformlycircumferentially-spaced ports 134 extending radially from cylindricalsection 131 b of outer surface 131 to bore 133. In this embodiment,ports 134 are generally elliptically shaped and angularly spaced 180°apart about axis 105.

Referring now to FIGS. 5 and 11-14, inlet guide 140 is disposed aboutrotor 130 within connection sub 110 and seated against upper end 121 aof housing 121. In addition, inlet guide 140 has a first or upper end140 a, a second or lower end 140 b axially abutting housing 121, aradially inner surface 141 extending axially between ends 140 a, 140 b,and a radially outer surface 145 extending axially between ends 140 a,140 b. Inner surface 141 of inlet guide 140 includes a first cylindricalsection 142 a extending axially from upper end 140 a to an upward-facingannular planar shoulder 142 b and a second cylindrical section 142 cextending axially from lower end 140 b to shoulder 142 b. Cylindricalsection 142 a is disposed at a diameter that is greater than thediameter of cylindrical section 142 c.

Outer surface 145 of inlet guide 140 includes a plurality of uniformlycircumferentially-spaced parallel flights 146 that extend helicallyabout axis 105 and axially between ends 140 a, 140 b. In thisembodiment, inlet guide 140 includes three uniformlycircumferentially-spaced flights 146. Thus, flights 146 are angularlyspaced 120° apart about axis 105. However, in general, the inlet guide(e.g., inlet guide 140) can include any suitable number of flights(e.g., two, three, four, or more flights 146), and further, the flightscan be uniformly or non-uniformly circumferentially-spaced. Each flight146 has a radially inner base 147 a integral with the remainder of inletguide 140 and a radially outer generally cylindrical surface 147 bdistal the remainder of inlet guide 140. Surface 147 b of each flight146 is disposed at a uniform radius R_(147b), and each flight 146 has aheight H₁₄₆ measured radially from its base 147 a to its outer surface147 b. Surfaces 147 b of flights 146 statically engage secondcylindrical section 112 b of connection sub 110, and thus, radiusR_(147b) of each radially outer surface 147 b is substantially the sameas the inner radius of connection sub 110 along second cylindricalsection 112 b. In general, the radius R₁₄₇ b of each outer surface 147 bis preferably between 1/16 and 2.0 in., and each height H₁₄₆ ispreferably between 1/16 and 2.0 in. In this embodiment, radius R_(147b)of each outer surface 147 b is the same, and in particular, is ¼ in.;and each height H₁₄₆ of each flight 146 is the same, and in particular,is ⅜ in. In addition, each flight 146 is oriented at an acute flightangle θ₁₄₆ relative to a reference plane A perpendicular to axis 105 inside view, and has a pitch P₁₄₆ equal to the axial length(center-to-center) of one complete turn of flight 146. Flight angle θ₁₄₆of each flight 146 is preferably between 0° and 90°, and more preferablybetween 30° and 60°. Pitch P₁₄₆ of each flight 146 is preferably between1/24 and ⅓ revolutions over 1.0 in. In this embodiment, flights 146 areidentical and parallel, and thus, radius R_(147b) of each outer surface147 b is the same, flight angle θ₁₄₆ of each flight 146 is the same andpitch P₁₄₆ of each flight 146 is the same. In particular, in thisembodiment, flight angle θ₁₄₆ of each flight 146 is 45° and pitch P₁₄₆of each flight 146 is 1/12 revolutions over 1.0 in. As best shown inFIG. 13, when the inlet guide 140 is viewed from above along axis 105,flights 146 spiral in a clockwise direction. Thus, flights 136 of rotor130 and flights 146 of inlet guide 140 spiral in opposite directions. Asa result, the angle between flights 136, 146 is the sum of flight anglesθ₁₃₆, θ₁₄₆. In embodiments described herein, the sum of flight anglesθ₁₃₆, θ₁₄₆ is preferably between 0° and 180°, and more preferably about90°. In this embodiment, flight angles θ₁₃₆, θ₁₄₆ are 45°, 45°,respectively, and thus, the angle between flights 136, 146 is 90°.

In this embodiment, outer surface 145 also includes a plurality ofcircumferentially adjacent parallel grooves 149 disposed between eachpair of circumferentially adjacent flights 146. Grooves 149 offer thepotential to facilitate and assist fluid flow through drive assembly120.

Referring now to FIGS. 15 and 16, guide shoe 180 is an elongate memberhaving a central axis coaxially aligned with axis 105, a first or upperend 180 a, a second or lower end 180 b coincident with end 100 b, and anouter surface 181 extending axially between ends 180 a, 180 b. In thisembodiment, outer surface 181 includes a convex semi-spherical curvedtip 182 a at end 180 b, a cylindrical section 182 b extending axiallyfrom end 180 a to tip 182 a, and a tapered frustoconical surface 182 cextending from end 180 b. Tapered frustoconical surface 182 c terminatesbetween ends 180 a, 180 b, and thus, does not extend to end 180 a. Dueto tapered frustoconical surface 182 c, tip 182 a has a centerline 185that is oriented parallel to axis 105 and radially offset from axis 185,and further, the outer perimeter of guide shoe 180 measured in a planeoriented perpendicular to axes 105, 185 increases moving axially fromtip 182 a. This also results in outer surface 181 having a generallyoblique cone geometry. It should be appreciated that outer surface 180is smoothly and continuously contoured. As used herein, the term“continuously contoured” may be used to describe surfaces and profilesthat are smoothly and continuously curved so as to be free of sharpedges and/or transitions with radii less than 0.5 in. As best shown inFIG. 15, tapered frustoconical surface 182 c is oriented at an acuteangle α_(182c) relative to axes 105, 185. Angle α_(182c) is preferablybetween 8° and 15°. In this embodiment, angle α_(182c) is 10°. Angleα_(182c) allows the tapered frustoconical surface 182 c to pass throughthe axis 105 such that there is a tapered surface rather than a flatshoulder coming into contact with any potential restrictions or ledgeswithin the wellbore 20.

Referring still to FIGS. 15 and 16, guide shoe 180 also includes acentral bore 186 extending axially from end 180 a and defining an innersurface 187 within guide shoe 180 Moving axially along throughbore 186from end 180 a, inner surface 187 includes a first cylindrical section188 a extending axially from end 180 a, an upward-facing annular planarshoulder 188 b, a second cylindrical section 188 c, an internallythreaded section 188 d, an upward-facing annular planar shoulder 188 e,and a third cylindrical section 188 f. A plurality of ports 189 extendfrom section 188 f to outer surface 181. Third cylindrical section 188 fdefines an inner fluid cavity 190 within guide shoe 180 that receivesfluid during run-in operations. The fluid is distributed from cavity 190to ports 189. In this embodiment, ports 189 include a plurality ofcircumferentially-spaced radial ports 189 a that extend radially fromcavity 190 to outer surface 181 and an axial port 189 b that extendsaxially from cavity 190 to outer surface 181. As best shown in FIG. 16,in this embodiment, guide shoe 180 also includes a plurality ofcircumferentially-spaced internally threaded bores 195 extendingradially from second cylindrical portion 188 c to outer surface 181.

Internal threads of threaded section 188 d threadably engage matingexternal threads of threaded section 131 g of rotor 130, therebythreadably coupling guide shoe 180 to end 130 b of rotor 130. With guideshoe 180 sufficiently threaded onto end 130 b (i.e., with end 130 baxially abutting shoulder 188 e, a set screw 196 (see FIG. 18) isthreaded through each bore 195 and into engagement with recess 131 f ofrotor 130. With the radially inner ends of set screws 196 seated inrecess 131 f, guide shoe 180 is prevented from moving axially relativeto rotor 130. Thus, guide shoe 180 cannot unthread from rotor 130 orrotate relative to rotor 130 with set screws 196 seated in recess 131 f.

Referring again to FIG. 3, guide assembly 100 also includes a pair ofbearing assemblies 150, 160 that maintain the coaxial alignment of rotor130 within housing 121, support radial and axial loads between rotor 130and inlet guide 140/housing 121, support axial loads between housing 121and guide shoe 180, and allow rotation of rotor 130 and guide shoe 180relative to housing 121. First bearing assembly 150 is radiallypositioned between inlet guide 140 and cylindrical section 131 b ofrotor 130, and axially positioned between spacer 170 and shoulder 132 aof rotor 130; and second bearing assembly 160 is radially positionedbetween housing 121/guide shoe 180 and cylindrical section 131 d ofrotor 130, and axially positioned between shoulders 126 d, 188 b.

Referring now to FIG. 17, first bearing assembly 150 supports radialloads and axial thrust loads between rotor 130 and inlet guide 140 whileallowing rotor 130 to rotate relative to inlet guide 140. In particular,first bearing assembly 150 includes a radial bearing 151, which supportsradial loads between rotor 130 and inlet guide 140 while allowing rotor130 to rotate relative to inlet guide 140, and a thrust bearing 155,which supports thrust loads between rotor 130 and inlet guide 140 whileallowing rotor 130 to rotate relative to inlet guide 140. Thrust bearing155 is axially compressed between spacer 170 and annular shoulder 142 bof inlet guide 140, and radial bearing 151 is positioned axiallyadjacent thrust bearing 155 between cylindrical sections 131 c, 142 c ofrotor 130 and inlet guide 140, respectively. Thrust bearing 155 isprevented from moving axially by spacer 170 and shoulder 142 b, andradial bearing 151 is coupled to thrust bearing 155 such that radialbearing 151 cannot move axially relative to thrust bearing 155.

Referring still to FIG. 17, in this embodiment, radial bearing 151 is aneedle roller bearing including an annular race 152 disposed about rotor130 and a plurality of circumferentially-spaced elongate cylindricalroller elements 153 circumferentially disposed about rotor 130. Race 152is radially positioned between cylindrical sections 131 c, 142 c ofrotor 130 and inlet guide 140, respectively, and rollers 153 areradially positioned between race 152 and cylindrical section 131 c ofrotor 130. Race 152 engages cylindrical section 142 c of inlet guide 140and is stationary relative to inlet guide 140 (i.e., race 152 does notrotate relative to inlet guide 140). However, roller elements 153rotatably engage race 152 and cylindrical section 131 c, and thus,rotate relative to race 152 and rotor 130. Each roller element 153 hasan axis of rotation oriented parallel to axis 105, thereby allowingrotor 130 to rotate about axis 105 relative to race 152 and inlet guide140 while transferring radial loads between rotor 130 and inlet guide140. A cage (not shown) maintains the circumferential-spacing of rollerelements 153.

In this embodiment, thrust bearing 155 is a roller bearing including afirst annular race 156 disposed about rotor 130, a second annular race157 disposed about rotor 130 and axially spaced from race 156, and aplurality of circumferentially-spaced cylindrical roller elements 158disposed about rotor 130 and axially positioned between races 156, 157.First race 156 axially abuts spacer 170 and is stationary relative tospacer 170 (i.e., race 156 does not rotate relative to spacer 170),second race 157 is seated against shoulder 142 b and is stationaryrelative to inlet guide 140 (i.e., race 157 does not rotate relative toinlet guide 140), and roller elements 158 rotatably engage races 156,157, and thus, rotate relative to races 156, 157. A retaining coverholds the races 156, 157 together until the make-up of spacer 170 andretention cap 175 on externally threaded section 131 a of rotor 130 atend 130 a holds the bearing 155 in place. Each roller element 158 has anaxis of rotation that is oriented perpendicular to axis 105 andintersects axis 105, thereby allowing races 156, 157 to rotate relativeto each other. A cage (not shown) maintains the circumferential-spacingof roller elements 158.

Referring now to FIG. 18, second bearing assembly 160 supports radialloads and axial thrust loads between rotor 130 and housing 120 whileallowing rotor 130 to rotate relative to housing 121. In particular,second bearing assembly 160 includes a radial bearing 161, whichsupports radial loads between rotor 130 and housing 121 while allowingrotor 130 to rotate relative to housing 121, and a thrust bearing 165,which supports thrust loads between rotor 130 and housing 121 and upperend 180 a of guide shoe 180 while allowing rotor 130 to rotate relativeto housing 121. Thrust bearing 165 is axially positioned between radialbearing 161 and shoulder 188 b, and radial bearing 161 is axiallypositioned between thrust bearing 165 and shoulder 126 d. Thrust bearing165 is prevented from moving axially by outer housing lower end 121 band shoulder 188 b, and radial bearing 161 is coupled to thrust bearing165 such that radial bearing 161 cannot move axially relative to thrustbearing 165.

Referring still to FIG. 18, in this embodiment, radial bearing 161 is aneedle roller bearing including an annular race 162 disposed about rotor130 and a plurality of circumferentially-spaced elongate cylindricalroller elements 163 circumferentially disposed about rotor 130. Race 162is radially positioned between cylindrical sections 131 e, 126 e ofrotor 130 and housing 121, respectively, and rollers 163 are radiallypositioned between race 162 and cylindrical section 131 e of rotor 130.Race 162 engages cylindrical section 126 e of housing 121 and isstationary relative to housing 121 (i.e., race 162 does not rotaterelative to housing 121). However, roller elements 163 rotatably engagerace 162 and cylindrical section 131 e, and thus, rotate relative torace 162 and rotor 130. Each roller element 163 has an axis of rotationoriented parallel to axis 105, thereby allowing rotor 130 to rotateabout axis 105 relative to race 162 and housing 121 while transferringradial loads between rotor 130 and housing 121. A cage (not shown)maintains the circumferential-spacing of roller elements 163.

In this embodiment, thrust bearing 165 is a roller bearing including afirst annular race 166 disposed about rotor 130, a second annular race167 disposed about rotor 130 and axially spaced from race 166, and aplurality of circumferentially-spaced cylindrical roller elements 168disposed about rotor 130 and axially positioned between races 166, 167.First race 166 axially abuts race 162 and is stationary relative to race162 (i.e., race 166 does not rotate relative to race 162), second race167 is seated against shoulder 188 b and is stationary relative to guideshoe 180 (i.e., race 167 does not rotate relative to guide shoe 180),and roller elements 168 rotatably engage races 166, 167, and thus,rotate relative to races 166, 167. A retaining cover holds the races166, 167 axially together. Each roller element 168 has an axis ofrotation that is oriented perpendicular to axis 105 and intersects axis105, thereby allowing races 166, 167 to rotate relative to each other. Acage (not shown) maintains the circumferential-spacing of rollerelements 168.

Referring now to FIGS. 5 and 17, retention cap 175 is generallycylindrical and has a first or upper end 175 a disposed in connectionsub 110, a second or lower end 175 b disposed about rotor 130, and aradially outer surface 175 c extending axially between ends 175 a, 175b. In addition, retention cap 175 includes a bore 176 extending axiallyfrom end 175 b and a plurality of circumferentially-spaced internallythreaded bores 177 extending radially from outer surface 175 c to bore176. A portion of bore 176 includes internal threads that threadablyengage mating external threads of threaded section 131 a of rotor 130,thereby threadably coupling retention cap 175 to end 130 a of rotor 130.With retention cap 175 sufficiently threaded onto end 130 a, a set screw178 is threaded through each bore 177 and into engagement with recess131 b of rotor 130. With the radially inner ends of set screws 178seated in recess 131 b, retention cap 175 is prevented from movingaxially relative to rotor 130. Thus, retention cap 175 cannot unthreadfrom rotor 130 or rotate relative to rotor 130 with set screws 178seated in recess 131 b.

As best shown in FIG. 17, as retention cap 175 is threaded onto end 130a of rotor 130, spacer 170, thrust bearing 155, and inlet guide 140 areaxially compressed between ends 175 b, 121 a. In particular, spacer 170is axially compressed between retention cap 175 and thrust bearing 155,thrust bearing 155 is axially compressed between spacer 170 and shoulder142 b of inlet guide 140, and inlet guide 140 is axially compressedbetween thrust bearing 155 and end 121 a of housing 121, whichthreadably engages end 110 b of connection sub 110. As previouslydescribed, flight surfaces 147 b of inlet guide 140 statically engagesecond cylindrical section 112 b of connection sub 110. Thus, retentioncap 175, spacer 170, thrust bearing first annular race 156, and rotor130 rotate relative to housing 121, connection sub 110, inlet guide 140,radial bearing annular race 152, and thrust bearing second annular race157.

As previously described, in this embodiment, outer surface 181 of guideshoe 180 has a generally oblique cone geometry. However, guide shoeshaving alternative geometries can also be used in assembly 100 in placeof guide shoe 180. Referring now to FIGS. 19A-19D, alternativeembodiments of guide shoes 280, 380, 480, 580, respectively, which canbe used in place of guide shoe 180, are schematically shown. In FIG.19A, guide shoe 280 has a central axis 285, a first or upper end 280 aconfigured to attached to lower end 130 b of rotor 130, a second orlower end 280 b, and an outer surface 281 extending axially between ends280 a, 280 b. When guide shoe 280 is attached to rotor 130, axis 285 iscoaxially aligned with axis 105. In this embodiment, outer surface 281is concentrically disposed about axis 285 and includes a cylindricalsection 282 a extending axially from end 280 a and a frustoconicalsection 282 b extending from end 280 b to cylindrical section 282 a andoriented at an acute angle β_(282b) relative to axes 105, 285.

In FIG. 19B, guide shoe 380 has a central axis 385, a first or upper end380 a configured to attached to lower end 130 b of rotor 130, a secondor lower end 380 b, and an outer surface 381 extending axially betweenends 380 a, 380 b. When guide shoe 380 is attached to rotor 130, axis385 is coaxially aligned with axis 105. In this embodiment, outersurface 381 is concentrically disposed about axis 385 and includes acylindrical section 382 a extending axially from end 380 a and afrustoconical section 382 b extending from end 380 b to cylindricalsection 382 a and oriented at an acute angle β_(382b) relative to axes105, 385. Guide shoe 380 further includes a plurality of uniformlycircumferentially-spaced ports 383 extending radially from frustoconicalsection 382 b of outer surface 381 to an inner fluid cavity (not shown)extending axially from upper end 380 a and lower end 380 b. In thisembodiment, frustoconical section 382 b is oriented at an acute angleβ_(382b) that is greater than the acute angle β_(282b) at which thefrustoconical section 282 b of the guide shoe 280 shown in FIG. 19A isoriented.

In FIG. 19C, guide shoe 480 has a central axis 485, a first or upper end480 a configured to attached to lower end 130 b of rotor 130, a secondor lower end 480 b, and an outer surface 481 extending axially betweenends 480 a, 480 b. When guide shoe 480 is attached to rotor 130, axis485 is coaxially aligned with axis 105. In this embodiment, outersurface 481 is concentrically disposed about axis 485 and includes aconvex semi-spherical curved tip 482 b at end 480 b and a cylindricalsection 482 a extending axially from end 480 a to tip 482 b. Guide shoe380 further includes a plurality of uniformly circumferentially-spacedports 483 extending radially from tip 482 b of outer surface 481 to aninner fluid cavity (not shown) extending axially from upper end 480 aand lower end 480 b.

In FIG. 19D, guide shoe 580 has a central axis 585, a first or upper end580 a configured to attached to lower end 130 b of rotor 130, a secondor lower end 580 b, and an outer surface 581 extending axially betweenends 580 a, 580 b. When guide shoe 580 is attached to rotor 130, axis585 is coaxially aligned with axis 105. In this embodiment, outersurface 581 is concentrically disposed about axis 585 and includes afirst cylindrical section 582 a extending axially from end 580 a to adownward-facing annular frustoconical shoulder 582 b, a secondcylindrical section 582 c extending axially from shoulder 582 b to atapered frustoconical surface 582 d extending from end 580 b tocylindrical section 582 c. Second cylindrical section 582 c is disposedat a diameter that is less than the diameter of first cylindricalsection 582 a. Guide shoe 580 further includes a plurality ofnon-uniformly non-circumferentially-spaced ports 583 a. 583 b extendingradially from tapered frustoconical surface 582 d of outer surface 581to an inner fluid cavity (not shown) extending axially from upper end580 a and lower end 580 b. Thus, guide shoe 580 has an eccentricgeometry and is eccentrically weighted.

Referring now to FIGS. 1, 3, and 5 during run-in operations, guideassembly 100 is connected to the lower end of liner 50 and advanceddownhole with injector head unit 14. As guide assembly 100 leads liner50 through borehole 20, fluid (e.g., drilling fluid) is pumped from thesurface 30 down liner 50 to guide assembly 100. The fluid flows axiallythrough guide assembly 100 between housing 121 and inlet guide 140/rotor130. As fluid is pumped axially between housing 121 and inlet guide 140,the fluid exerts forces on helical flights 146, which are oriented atangles θ₁₄₆ relative the axial direction (i.e., along axis 105) (seeFIG. 11). However, inlet guide 140 is static relative to housing 121,and thus, inlet guide 140 resists the forces and torque applied toflights 146 by the fluid. As a result, inlet guide 140 does not rotatein response to the flow of fluid over helical flights 146, but rather,helical flights 146 direct of flow of the fluid in a generally clockwisedirection (when viewed from above) about axis 105 (see FIG. 13). Asfluid is pumped axially between housing 121 and rotor 130, the fluidexerts forces on helical flights 136, which are oriented at angles θ₁₃₆relative the axial direction (i.e., along axis 105) (see FIG. 8). Unlikeinlet guide 140, rotor 130 is rotatable relative to housing 121, andthus, rotor 130 rotates in response to the forces and torque applied toflights 136 by the fluid as the fluid flows axially through guideassembly 100. Helical flights 136 extend helically in a counterclockwisedirection (as viewed from above) about axis 105 (see FIG. 10), and thus,as the fluid flows between rotor 130 and housing 121, rotor 130 rotatesin a clockwise direction (as viewed from above). As previouslydescribed, flights 136 of rotor 130 are oriented at about 90° relativeto flights 146 of inlet guide 140, and thus, fluid flowing helicallyaround inlet guide 140 impacts flights 136 of rotor 130 at about 90°,which offers the potential to maximize the impact force and associatedrotational torque applied to rotor 130.

The lower end 130 b of rotor 130 is fixably attached to guide shoe 180,and thus, rotation of rotor 130 relative to housing 121 about axis 105results in the rotation of guide shoe 180 relative to housing 121 aboutaxis 105. The rotation of the guide shoe 180 allows guide assembly 100to guide liner 50 around obstructions in the borehole 20. In thisembodiment, rotor 130 is concentrically disposed within housing 121,rotates about central axis 105, and flights 136 are uniformlycircumferentially-spaced and have the same geometry. Consequently, rotor130 has a center of mass disposed along rotational axis 105, and thus,is generally rotationally balanced. Guide shoe 180 also rotates aboutaxis 105; however, guide shoe 180 has an eccentric geometry and iseccentrically weighted. In particular, due at least in part to tip 182 abeing radially offset from axis 105, guide shoe 180 has a center of massthat is offset from rotational axis 105. Consequently, as guide shoe 180rotates about axis 105, imbalanced forces and associated vibrations areinduced, which advantageously offer the potential to enhance the abilityof guide assembly 100 to guide liner 50 around obstructions in theborehole 20 and reduce the likelihood of guide assembly 100 getting hungup or stuck downhole.

Referring now to FIGS. 1, 5, 6, 8, 9, and 16, the fluid flowing betweenrotor 130 and housing 121 flows radially inward through ports 134 intobore 133 of rotor 130, and then from bore 133 through cavity 190 andports 189 of guide shoe 180 into the borehole 20. The fluid in borehole20 can then flow up the annulus 24 to the surface 30. During run-in,drilling fluid can be pumped down liner 50 and guide assembly 100, andback up annulus 24 to facilitate the advancement of guide assembly 100and liner through borehole 20. However, once liner 50 is run to thedesired depth/location within borehole 20, cement can be pumped downliner 50 and guide assembly 100, and back up annulus 24 to secure liner50 in the desired position within borehole 20.

As previously described, imbalanced forces and associated vibrationsexperienced by guide assembly 100 advantageously offer the potential toenhance the ability of guide assembly 100 to guide liner 50 aroundobstructions in the borehole 20 and reduce the likelihood of guideassembly 100 getting hung up or stuck downhole. In general, imbalancedforces and associated vibrations can be induced by an eccentric guideshoe and/or an eccentric rotor. In the embodiment of guide assembly 100shown in FIG. 2, such imbalanced forces and vibrations result from theeccentric geometry and weight distribution of guide shoe 180. However,in other embodiments, the imbalanced forces and associated vibrationsare induced by an eccentrically weighted rotor. For example, portions ofmaterial can be removed from select locations of a rotor (e.g., drillingholes in one or more helical flights of the rotor, making one helicalflight shorter than the other helical flights, etc.) to form aneccentrically weighted rotor.

While preferred embodiments have been shown and described, modificationsthereof can be made by one skilled in the art without departing from thescope or teachings herein. The embodiments described herein areexemplary only and are not limiting. Many variations and modificationsof the systems, apparatus, and processes described herein are possibleand are within the scope of the invention. For example, the relativedimensions of various parts, the materials from which the various partsare made, and other parameters can be varied. Accordingly, the scope ofprotection is not limited to the embodiments described herein, but isonly limited by the claims that follow, the scope of which shall includeall equivalents of the subject matter of the claims. Unless expresslystated otherwise, the steps in a method claim may be performed in anyorder. The recitation of identifiers such as (a), (b), (c) or (1), (2),(3) before steps in a method claim are not intended to and do notspecify a particular order to the steps, but rather are used to simplifysubsequent reference to such steps.

What is claimed is:
 1. A guide assembly for running a liner through aborehole extending through a subterranean formation, the guide assemblyhaving a central axis, a first end configured to be coupled to theliner, and a second end opposite the first end, the guide assemblycomprising: a guide shoe disposed at the second end; a drive assemblyincluding a radially outer housing and a rotor concentrically disposedin the housing, wherein the rotor is configured to rotate about thecentral axis relative to the housing about the central axis; wherein therotor has a first end distal the guide shoe and a second end fixablycoupled to the guide shoe.
 2. The guide assembly of claim 1, wherein therotor includes a plurality of circumferentially-spaced parallel helicalflights.
 3. The guide assembly of claim 2, wherein the plurality ofhelical flights of the rotor are radially spaced from the housing. 4.The guide assembly of claim 2, further comprising an inlet guideincluding a plurality of circumferentially-spaced parallel helicalflights.
 5. The guide assembly of claim 4, wherein the rotor isconfigured to rotate relative to the inlet guide.
 6. The guide assemblyof claim 4, wherein the plurality of helical flights of the inlet guidestatically engage a cylindrical inner surface of the outer housing. 7.The guide assembly of claim 4, wherein the plurality of helical flightsof the inlet guide spiral about the central axis in a first directionand the helical flights of the rotor spiral about the central axis in asecond direction that is opposite the first direction.
 8. The guideassembly of claim 7, wherein each of the plurality of helical flights ofthe rotor are oriented at a flight angle A relative to a reference planeoriented perpendicular to the central axis and each of the plurality ofhelical flights of the inlet guide are oriented at a flight angle Brelative to the reference plane, and wherein the sum of angle A andangle B is between 0° and 180°.
 9. The guide assembly of claim 9,wherein the drive assembly includes a first radial bearing, a secondradial bearing, an first thrust bearing, and a second thrust bearing;wherein the first radial bearing is radially positioned between therotor and the inlet guide and the second radial bearing is radiallypositioned between the rotor and the housing; wherein the first thrustbearing is axially positioned between a spacer and the inlet guide andthe second thrust bearing is axially positioned between the housing andthe guide shoe.
 10. The guide assembly of claim 1, wherein the rotorincludes a bore extending axially from the second end of the rotor and aport extending radially from an outer surface of the rotor to the bore.11. The guide assembly of claim 10, wherein the guide shoe includes aninner fluid cavity in fluid communication with the bore of the rotor anda plurality of ports extending from the inner fluid cavity to an outersurface of the guide shoe.
 12. A guide assembly for running a linerthrough a borehole extending through a subterranean formation, the guideassembly having a central axis, a first end configured to be coupled tothe tubular, and a second end opposite the first end, the guide assemblycomprising: a guide shoe disposed at the second end; a drive assemblyincluding a radially outer housing and a rotor rotatably disposed in thehousing, wherein the rotor has a first end distal the guide shoe, asecond end fixably coupled to the guide shoe, and an outer surfaceextending from the first end of the rotor to the second end of therotor, wherein the outer surface of the rotor includes a plurality ofcircumferentially-spaced parallel helical flights; an inlet guidedisposed about the rotor and axially positioned between the first end ofthe rotor and the plurality of helical flights of the rotor, wherein theinlet guide has an outer surface including a plurality ofcircumferentially-spaced parallel helical flights; wherein each of thehelical flights of the rotor spiral about the central axis in a firstdirection and the plurality of helical flights of the inlet guide spiralabout the central axis in a second direction that is opposite the firstdirection.
 13. The guide assembly of claim 12, wherein the rotor iscoaxially disposed in the outer housing.
 14. The guide assembly of claim13, wherein the rotor is configured to rotate relative to the inletguide.
 15. The guide assembly of claim 14, wherein the plurality ofcircumferentially-spaced parallel helical flights of the inlet guidestatically engage the outer housing.
 16. The guide assembly of claim 12,wherein each of the plurality of helical flights of the rotor areoriented at a flight angle A relative to a reference plane orientedperpendicular to the central axis and each of the plurality of helicalflights of the inlet guide are oriented at a flight angle B relative tothe reference plane, and wherein the sum of angle A and angle B isbetween 0° and 180°.
 17. The guide assembly of claim 12, wherein therotor includes a bore extending axially from the second end of the rotorand a plurality of circumferentially-spaced ports extending radiallyfrom an outer surface of the rotor to the bore.
 18. The guide assemblyof claim 17, wherein the guide shoe includes an inner fluid cavity influid communication with the bore of the rotor and a plurality of portsextending from the inner fluid cavity to an outer surface of the guideshoe.
 19. A guide assembly for running a tubular through a boreholeextending through a formation, the guide assembly having a central axis,a first end configured to be coupled to the tubular, and a second endopposite the first end, the guide assembly comprising: a guide shoedisposed at the second end; and a drive assembly configured to drive therotation of the guide shoe about the central axis, wherein the driveassembly includes a radially outer tubular housing and a rotor rotatablydisposed within the housing, wherein the rotor has a first end distalthe guide shoe and a second end fixably coupled to the guide shoe,wherein the rotor includes a bore extending axially from the second endof the rotor and a port extending radially from an outer surface of therotor to the bore; wherein the guide shoe includes an inner fluid cavityin fluid communication with the bore of the rotor and a port extendingfrom the inner fluid cavity to an outer surface of the guide shoe. 20.The guide assembly of claim 19, wherein the rotor includes a pluralityof circumferentially-spaced parallel helical flights.
 21. The guideassembly of claim 20, further comprising an inlet guide including aplurality of circumferentially-spaced parallel helical flights, whereinthe rotor is configured to rotate relative to the inlet guide.
 22. Theguide assembly of claim 21, wherein the plurality of helical flights ofthe inlet guide statically engage the outer housing.
 23. The guideassembly of claim 22, wherein the plurality of helical flights of therotor spiral about the central axis in a first direction; and whereinthe plurality of helical flights of the inlet guide spiral about thecentral axis in a second direction that is opposite the first direction.24. The guide assembly of claim 23, wherein the guide shoe has aneccentric geometry and is eccentrically weighted.
 25. The guide assemblyof claim 23, wherein the rotor has an eccentric geometry and iseccentrically weighted.
 26. The guide assembly of claim 23, wherein theguide shoe and the rotor have an eccentric geometry and areeccentrically weighted.